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  • 1
    Electronic Resource
    Electronic Resource
    s.l. : American Chemical Society
    Journal of the American Chemical Society 100 (1978), S. 7742-7743 
    ISSN: 1520-5126
    Source: ACS Legacy Archives
    Topics: Chemistry and Pharmacology
    Type of Medium: Electronic Resource
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  • 2
    ISSN: 1432-0630
    Keywords: 61.70 ; 81
    Source: Springer Online Journal Archives 1860-2000
    Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Physics
    Notes: Abstract By means of an integrated source-specimen technique the temperature dependence of positron lifetimes and annihilation lineshapes has been measured, on the same specimens of gold and cadmium from 4.2K to the melting points, and also in electronirradiated and quenched gold. The anomalous temperature dependence of positron annihilation at intermediate temperatures (200 to 350 K in Cd, 270 to 750 K in Au) discovered by Lichtenberger, Schulte, and MacKenzie is confirmed. The data are incompatible with the idea that the intermediate temperature dependence is due to thermal expansion. They are well explained by an extension of the trapping model which includes the formation of metastable self-trapped positrons. From lineshape measurements after electron irradiation at 180 K and after quenching it is deduced that the trapping rate of positrons at vacancy-type defects in Au is temperature independent below room temperature.
    Type of Medium: Electronic Resource
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  • 3
    Electronic Resource
    Electronic Resource
    Springer
    Naturwissenschaften 67 (1980), S. 606-607 
    ISSN: 1432-1904
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology , Natural Sciences in General
    Type of Medium: Electronic Resource
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  • 4
    Electronic Resource
    Electronic Resource
    Springer
    Applied physics 22 (1980), S. 185-187 
    ISSN: 1432-0630
    Keywords: 06 ; 07 ; 61.70
    Source: Springer Online Journal Archives 1860-2000
    Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Physics
    Notes: Abstract New methods for thermal-equilibrium investigations of atomic vacancies or of dislocation movements in metals require measurements of minute resistance fluctuations. The accuracy of such measurements is limited by thermal noise from the resistor. The present paper proposes a method for analysing resistance fluctuations independent of voltage noise.
    Type of Medium: Electronic Resource
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  • 5
    Electronic Resource
    Electronic Resource
    Springer
    Applied physics 30 (1983), S. 117-122 
    ISSN: 1432-0630
    Keywords: 61.70 ; 72.70
    Source: Springer Online Journal Archives 1860-2000
    Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Physics
    Notes: Abstract Fluctuations in the number of vacancies in metals in thermal equilibrium lead to resistivity fluctuations. Analysis of these fluctuations permits measurement of both formation and migration enthalpy of the vacancies. The power spectrum of the fluctuations is calculated using a series of statistically independent pulses. It can be derived from the diffusion equation for any geometry of the vacancy sinks. Vacancy diffusion to the surface of a thin plate or of a sphere are treated as examples. The measurability of vacancy noise is assessed. It should also be possible to measure vacancy noise during irradiation. It is predicted that correlated vacancy creation, which may occur during irradiation, will cause an increase in the power spectrum.
    Type of Medium: Electronic Resource
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  • 6
    Electronic Resource
    Electronic Resource
    Springer
    Fresenius' Zeitschrift für analytische Chemie 304 (1980), S. 262 
    ISSN: 1618-2650
    Keywords: Natrium-Cluster ; Strukturbest. bis Na8 ; Pseudopotentialrechnung
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Type of Medium: Electronic Resource
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  • 7
    Electronic Resource
    Electronic Resource
    New York, NY : Wiley-Blackwell
    International Journal of Quantum Chemistry 9 (1975), S. 775-787 
    ISSN: 0020-7608
    Keywords: Computational Chemistry and Molecular Modeling ; Atomic, Molecular and Optical Physics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: A method is described for calculating cohesive energies of solids in the single-determinant approximation including the full Hartree-Fock exchange. The method involves (1) the construction of a rapidly convergent series in vectors of the direct and reciprocal lattice for the Fock matrix, (2) a decoupling procedure for the k-dependence of the Fock matrix, which works even in the case of strong interatomic overlap. An application to Li and Be is given. Agreement with experiment to 10% is achieved for the cohesive energies and to 5% for the equilibrium lattice constants.
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
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  • 8
    Electronic Resource
    Electronic Resource
    New York, NY : Wiley-Blackwell
    International Journal of Quantum Chemistry 19 (1981), S. 113-130 
    ISSN: 0020-7608
    Keywords: Computational Chemistry and Molecular Modeling ; Atomic, Molecular and Optical Physics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Semilocal pseudopotentials have been determined for first-row (Li to Ne), second row (Na to Ar), and third-row atoms (K, Ca). Core-valence correlation is included by adjusting the pseudopotentials to experimental energies of ions with a single valence electron. Correlation within the valence shell is taken into account by using the spin-density functional formalism. The approximations involved in this approach are tested for atomic ionization energies as well as binding energies of monohydrides and alkali diatomics, agreement with experiment is usually satisfactory, but in certain applications density functionals should be already included in the fitting of the local part of the pseudopotential. In addition, 3s/3p and 3s/2p basis sets (for first and second row, respectively), designed for use in connection with our pseudopotentials, are given; it is shown that they yield reasonable results for both SCF and correlation energies.
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
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  • 9
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Zeitschrift für anorganische Chemie 442 (1978), S. 221-224 
    ISSN: 0044-2313
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: About the Fluorescence Thermochromism of Acetonitrile Copper Iodide with Dibenzo-18-Crown-6Copper iodide reacts in actonitrile solution with dibenzo-18-crown-6 to form a compound,(CuJ)4(CH3CN)4(db-18-c-6), which fluoresces yellow at 298K, but pink at 77 K. It decomposes at 55.3°C. (5 Torr) by lost of acetonitrile and a heterogeneous mixture of copper iodide and polyether results. In absence of dibenzo-18-crown-6, copper iodide forms with acetonitrile a heterogeneous mixture of copper iodide and polyether results. In absence of dibenzo-18-crown-6, copper iodide forms with acetonitrile a solvate CuJ. CH3CN. It also shows fluorescence thermochromism (yellow at 298 K, but green at 77 k) but decomposes at 0°C and 760 Torr.The luminescences pectra of the macrocyclic polyether complex at 298 K is redshifted. This probably results from intersection between the crown and the acetonitrile copper iodide.
    Notes: Kupferjodid bildet in Acetonitril mit Dibenzo-18-Krone-6 eine Verbindung der Zusammensetzung (CuJ)4(CH3CN)4(db-18-c-6), die bei Raumtemperatur gelb, bei 77K rosa fluoresziert. Sie zersetzt sich bei 55,3°C (5 Torr) unter Verlust von Acetonitril zu einem heterogenen Gemenge aus Kronenäther Kupferjodid.In Abwesenheit von Kronenäther bildet Kupferjodid in Acetonitril ein Solvat CuJ · CH3CN. Es ist ebenfalls fluoreszenzthermochrom (gelb bei 298 K, grün bei 77 K) und zersetzt sich allerdings schon bei 0°C( 760 Torr). Das Lumineszenzspektrum des makrocyclischen Polyätherkomplexes ist bei 298 K rotverschoben, was wahrscheinlich auf die Wechselwirkung des Kronenäthers mit dem Acetonitrilo-Kupferjodid zurückzuführen ist.
    Additional Material: 3 Tab.
    Type of Medium: Electronic Resource
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  • 10
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Zeitschrift für anorganische Chemie 480 (1981), S. 193-198 
    ISSN: 0044-2313
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: New Results on Fluorescence Properties of Sesqui-, Bis- and Tris(triphenylphosphane) Copper(I) HalidesThe solid state fluorescence and excitation spectra of sequi-, bis- and tris(triphenylphosphane) copper(I) halides  -  (CuHal)2(PΦ3)3; CuHal(PΦ3)2; CuHal(PΦ3)3  -  at 300 K and 77 K are now completely registrated. The fluorescence is almost independent of the halide anion, whereas excitation is influenced. Furthermore, solvate molecules do not change the fluorescence. Dimeric sesqui compounds show a red shift of emission when cooled, but monomeric bis and tris complexes undergo a blue shift of emission by cooLing.
    Notes: Die Fluoreszenz- und Anregungsspektren der Sesqui-, Bis- und Tris(triphenylphosphan)kupfer(I)-Halogenide  -  (CuHal)2(PΦ3)3; CuHal(PΦ3)2; CuHal(PΦ3)3  -  im festen Zustand bei 300 K und 77 K liegen jetzt vollständig vor. Die Fluoreszenz ist nahezu unabhängig vom Halogenidion, wohingegen die Anregung beeinflußt wird. Weiterhin führen Solvatmoleküle zu keiner Fluoreszenzänderung. Beim Abkühlen von dimeren Sesqui-Verbindungen wird deren Emission nach rot verschoben, während die Emissionen monomerer Bis- und Tris-Verbindungen beim Abkühlen einer Blauverschiebung unterliegen.
    Additional Material: 1 Ill.
    Type of Medium: Electronic Resource
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